1. Field of the Invention
The present invention relates to a battery pack mounting structure for electric cars, and more particularly, relates to a battery pack mounting structure for electric cars for use to protect a battery pack mounted on an electric car which runs by a motor driving force from an impact force in the event of a rear impact.
2. Description of Related Art
Electric cars which run by a motor driving force need to have a larger battery capacity so as to run longer distances. At this point, when the battery capacity increases, a larger and heavier battery pack is required to store a battery. Thus, the battery pack is often mounted in a lower portion of a vehicle or a rear portion of the vehicle.
As a conventional battery pack mounting structure for electric cars, Japanese Patent Laid-Open No. 2004-161158 discloses a structure in which a plurality of battery packs are mounted in a longitudinal direction on the lower side of a rear floor, wherein a battery pack on the front side is mounted at a lower height above the ground than a battery pack on the rear side.
In the publication, a mount frame for mounting the battery packs on a vehicle body is composed of a front portion that extends in the vehicle longitudinal direction, a rear portion that is arranged at a position above the front portion and extends in the vehicle longitudinal direction, and a rising portion that connects both portions and extends in a vehicle vertical direction, and is formed in a step-like shape in side view such that the front portion having a front-side battery mounting surface is located at a lower height above the ground than the rear portion having a rear-side battery mounting surface.